package torrent import ( "container/heap" "context" "encoding/gob" "reflect" "runtime/pprof" "time" "unsafe" "github.com/anacrolix/log" "github.com/anacrolix/multiless" request_strategy "github.com/anacrolix/torrent/request-strategy" ) func (cl *Client) getRequestStrategyInput() request_strategy.Input { ts := make([]request_strategy.Torrent, 0, len(cl.torrents)) for _, t := range cl.torrents { if !t.haveInfo() { // This would be removed if metadata is handled here. We have to guard against not // knowing the piece size. If we have no info, we have no pieces too, so the end result // is the same. continue } rst := request_strategy.Torrent{ InfoHash: t.infoHash, ChunksPerPiece: t.chunksPerRegularPiece(), } if t.storage != nil { rst.Capacity = t.storage.Capacity } rst.Pieces = make([]request_strategy.Piece, 0, len(t.pieces)) for i := range t.pieces { p := &t.pieces[i] rst.Pieces = append(rst.Pieces, request_strategy.Piece{ Request: !t.ignorePieceForRequests(i), Priority: p.purePriority(), Partial: t.piecePartiallyDownloaded(i), Availability: p.availability, Length: int64(p.length()), NumPendingChunks: int(t.pieceNumPendingChunks(i)), IterPendingChunks: &p.undirtiedChunksIter, }) } t.iterPeers(func(p *Peer) { if p.closed.IsSet() { return } if p.piecesReceivedSinceLastRequestUpdate > p.maxPiecesReceivedBetweenRequestUpdates { p.maxPiecesReceivedBetweenRequestUpdates = p.piecesReceivedSinceLastRequestUpdate } p.piecesReceivedSinceLastRequestUpdate = 0 rst.Peers = append(rst.Peers, request_strategy.Peer{ Pieces: *p.newPeerPieces(), MaxRequests: p.nominalMaxRequests(), ExistingRequests: p.actualRequestState.Requests, Choking: p.peerChoking, PieceAllowedFast: p.peerAllowedFast, DownloadRate: p.downloadRate(), Age: time.Since(p.completedHandshake), Id: peerId{ Peer: p, ptr: uintptr(unsafe.Pointer(p)), }, }) }) ts = append(ts, rst) } return request_strategy.Input{ Torrents: ts, MaxUnverifiedBytes: cl.config.MaxUnverifiedBytes, } } func init() { gob.Register(peerId{}) } type peerId struct { *Peer ptr uintptr } func (p peerId) Uintptr() uintptr { return p.ptr } func (p peerId) GobEncode() (b []byte, _ error) { *(*reflect.SliceHeader)(unsafe.Pointer(&b)) = reflect.SliceHeader{ Data: uintptr(unsafe.Pointer(&p.ptr)), Len: int(unsafe.Sizeof(p.ptr)), Cap: int(unsafe.Sizeof(p.ptr)), } return } func (p *peerId) GobDecode(b []byte) error { if uintptr(len(b)) != unsafe.Sizeof(p.ptr) { panic(len(b)) } ptr := unsafe.Pointer(&b[0]) p.ptr = *(*uintptr)(ptr) log.Printf("%p", ptr) dst := reflect.SliceHeader{ Data: uintptr(unsafe.Pointer(&p.Peer)), Len: int(unsafe.Sizeof(p.Peer)), Cap: int(unsafe.Sizeof(p.Peer)), } copy(*(*[]byte)(unsafe.Pointer(&dst)), b) return nil } type ( RequestIndex = request_strategy.RequestIndex chunkIndexType = request_strategy.ChunkIndex ) type peerRequests struct { requestIndexes []RequestIndex peer *Peer torrentStrategyInput request_strategy.Torrent } func (p *peerRequests) Len() int { return len(p.requestIndexes) } func (p *peerRequests) Less(i, j int) bool { leftRequest := p.requestIndexes[i] rightRequest := p.requestIndexes[j] t := p.peer.t leftPieceIndex := leftRequest / p.torrentStrategyInput.ChunksPerPiece rightPieceIndex := rightRequest / p.torrentStrategyInput.ChunksPerPiece leftCurrent := p.peer.actualRequestState.Requests.Contains(leftRequest) rightCurrent := p.peer.actualRequestState.Requests.Contains(rightRequest) pending := func(index RequestIndex, current bool) int { ret := t.pendingRequests.Get(index) if current { ret-- } // See https://github.com/anacrolix/torrent/issues/679 for possible issues. This should be // resolved. if ret < 0 { panic(ret) } return ret } ml := multiless.New() // Push requests that can't be served right now to the end. But we don't throw them away unless // there's a better alternative. This is for when we're using the fast extension and get choked // but our requests could still be good when we get unchoked. if p.peer.peerChoking { ml = ml.Bool( !p.peer.peerAllowedFast.Contains(leftPieceIndex), !p.peer.peerAllowedFast.Contains(rightPieceIndex), ) } ml = ml.Int( pending(leftRequest, leftCurrent), pending(rightRequest, rightCurrent)) ml = ml.Bool(!leftCurrent, !rightCurrent) ml = ml.Int( -int(p.torrentStrategyInput.Pieces[leftPieceIndex].Priority), -int(p.torrentStrategyInput.Pieces[rightPieceIndex].Priority), ) ml = ml.Int( int(p.torrentStrategyInput.Pieces[leftPieceIndex].Availability), int(p.torrentStrategyInput.Pieces[rightPieceIndex].Availability)) ml = ml.Uint32(leftPieceIndex, rightPieceIndex) ml = ml.Uint32(leftRequest, rightRequest) return ml.MustLess() } func (p *peerRequests) Swap(i, j int) { p.requestIndexes[i], p.requestIndexes[j] = p.requestIndexes[j], p.requestIndexes[i] } func (p *peerRequests) Push(x interface{}) { p.requestIndexes = append(p.requestIndexes, x.(RequestIndex)) } func (p *peerRequests) Pop() interface{} { last := len(p.requestIndexes) - 1 x := p.requestIndexes[last] p.requestIndexes = p.requestIndexes[:last] return x } type desiredRequestState struct { Requests []RequestIndex Interested bool } func (p *Peer) getDesiredRequestState() (desired desiredRequestState) { input := p.t.cl.getRequestStrategyInput() requestHeap := peerRequests{ peer: p, } for _, t := range input.Torrents { if t.InfoHash == p.t.infoHash { requestHeap.torrentStrategyInput = t break } } request_strategy.GetRequestablePieces( input, func(t *request_strategy.Torrent, rsp *request_strategy.Piece, pieceIndex int) { if t.InfoHash != p.t.infoHash { return } if !p.peerHasPiece(pieceIndex) { return } allowedFast := p.peerAllowedFast.ContainsInt(pieceIndex) rsp.IterPendingChunks.Iter(func(ci request_strategy.ChunkIndex) { r := p.t.pieceRequestIndexOffset(pieceIndex) + ci //if p.t.pendingRequests.Get(r) != 0 && !p.actualRequestState.Requests.Contains(r) { // return //} if !allowedFast { // We must signal interest to request this desired.Interested = true // We can make or will allow sustaining a request here if we're not choked, or // have made the request previously (presumably while unchoked), and haven't had // the peer respond yet (and the request was retained because we are using the // fast extension). if p.peerChoking && !p.actualRequestState.Requests.Contains(r) { // We can't request this right now. return } } requestHeap.requestIndexes = append(requestHeap.requestIndexes, r) }) }, ) p.t.assertPendingRequests() heap.Init(&requestHeap) for requestHeap.Len() != 0 && len(desired.Requests) < p.nominalMaxRequests() { requestIndex := heap.Pop(&requestHeap).(RequestIndex) desired.Requests = append(desired.Requests, requestIndex) } return } func (p *Peer) maybeUpdateActualRequestState() bool { if p.needRequestUpdate == "" { return true } var more bool pprof.Do( context.Background(), pprof.Labels("update request", p.needRequestUpdate), func(_ context.Context) { next := p.getDesiredRequestState() more = p.applyRequestState(next) }, ) return more } // Transmit/action the request state to the peer. func (p *Peer) applyRequestState(next desiredRequestState) bool { current := &p.actualRequestState if !p.setInterested(next.Interested) { return false } more := true cancel := current.Requests.Clone() for _, ri := range next.Requests { cancel.Remove(ri) } cancel.Iterate(func(req uint32) bool { more = p.cancel(req) return more }) if !more { return false } for _, req := range next.Requests { if p.cancelledRequests.Contains(req) { // Waiting for a reject or piece message, which will suitably trigger us to update our // requests, so we can skip this one with no additional consideration. continue } // The cardinality of our desired requests shouldn't exceed the max requests since it's used // in the calculation of the requests. However, if we cancelled requests and they haven't // been rejected or serviced yet with the fast extension enabled, we can end up with more // extra outstanding requests. We could subtract the number of outstanding cancels from the // next request cardinality, but peers might not like that. if maxRequests(current.Requests.GetCardinality()) >= p.nominalMaxRequests() { //log.Printf("not assigning all requests [desired=%v, cancelled=%v, current=%v, max=%v]", // next.Requests.GetCardinality(), // p.cancelledRequests.GetCardinality(), // current.Requests.GetCardinality(), // p.nominalMaxRequests(), //) break } more = p.mustRequest(req) if !more { break } } p.updateRequestsTimer.Stop() if more { p.needRequestUpdate = "" if !current.Requests.IsEmpty() { p.updateRequestsTimer.Reset(3 * time.Second) } } return more }